Loop drier



A. O. HURXTHAL July 14, 1942.

LOOP DRIEB 4 Sheets-Sheet l Filed July '7. 1959 A. `O. HURXTHAL LooP DRIER July 14, 1942.

4 Sheets-Sheet 2 Filed July 7, 1939 a7 y f (f July 14 1942 v A. o. HURXTHAL 2,290,053.

LOOP DRIER Filed July '7, 1959 4 Sheets-Sheet 5 *J4 f@ @2] C) Q Q Q YQ Q QJ@ Q July 14, 1942. A. o. HuRxTl-:AL

LOOP DRIER Filed July 7, 1939 4 Sheets-Sheet 4 Patented July 14, 1942 LOOP DRIER Alpheus 0. Hurxthal, Proctor & Schwart phia, Pa., a corporatio Wyncote, Pa., assigner to Incorporated, Philadeln of Pennsylvania Application July 7, 1939, Serial No. 283,307

8 Claims.

This invention relates to improvements in festoon driers for web and like materials which can be hung in loops over poles and conveyed thereby through a drying chamber in which a suitable drying medium of desired temperature and humidity is circulated.

The invention more especially relates to the provision of a series of elongated nozzles in parallel relation to the loop supporting poles and positioned above the festoons thereon, with the mouths of the nozzles in vertical alignment with the spaces between the poles and directing the drying medium downwardly into the bellies of the festoons.

In the preferred embodiment of the invention, the nozzles are adapted to travel concurrently with the poles and the festoons supported thereby during the movement thereof through the drying chamber, in order to maintain the aforesaid relationship between the nozzles and the loop openings continuously,

If desired, the nozzles may advance in registry with the open ends of the festoons for a given distance along the path of movement of the poles and then return rapidly to the starting point, into registry with succeeding festoons, for a repeat of the cycle. In a further variation within the scope of the invention, the nozzles may be lheld stationary while the pole conveyer moves quickly, in intermittent steps, to an extent equal to ther distance between each two poles to bring the open ends of the loops successively into registry with the mouth slots of the succeeding nozzles.

The object of the invention, in either of the above cases, is to maintain the mouth slots of the nozzles in vertical alignment with the open ends of the festoon loops, formed in the spaces between the poles, for substantially the full travel of the festoons from the point of formation thereof, adjacent the feed end of the drier, to the point of withdrawal of the goods from the loops constituting the festoons, adjacent the discharge end of the drier.

The present invention constitutes an improvement to the drier disclosed in the applicants copending application, Serial No. 237,755, filed October 29, 1938, in that the construction of the nozzles in the present case lends itself efliciently to use with festoon conveyers having hold-down rollers respectively aligned with the poles and resting on the material lying over the top of each loop supporting pole, as the poles travel through the drying chamber.

' The construction and operation of the mechanism forming the subject matter of the present invention will be fully disclosed'hereinafter, reference being had to the accompanying drawings of which:

Fig. 1 is a diagrammatic longitudinal sectional elevation of a loop or festoon drier in which the concurrently traveling nozzles of the present invention have been incorporated;

Fig. 2 is a diagrammatic transverse sectional elevation taken on the line 2 2, Fig. 1;

Fig. 3 is a fragmentary longitudinal sectional elevati'on, drawn to an enlarged scale, of a portion of the mechanism diagrammatically shown in Fig. l;

Fig. 4 is a fragmentary transverse sectional elevation taken on the line 4 4, Fig, 3;

Fig. 5 illustrates a modification of the invention wherein the nozzles have an uneven reciprocatory movement longitudinally of the drying chamber; and

Fig. 6 diagrammatically illustrates the stationary nozzles and the pole conveyer movable quickly in intermittent steps.

As shown in Fig. 1, the drying or other processing apparatus comprises a casing I, through which web material W or the like which is to be treated therein is advanced from the feed end 2 to the discharge end 3 thereof. The web W is formed into a series of loops or festoons X over and between a series of supporting poles or girts I0. The supports I Il, in the present instance, are provided at their opposite ends respectively with trunnions I I which are rotatably mounted in suitable bearings formed in the side links of a e pair of laterally spaced side chains I2, I2 which,

together with the web supporting girts I il, I0, form an endless belt conveyer I3. The loops X, are respectively carried by the girts I0, I Il on the upper horizontal run I8 only of the conveyer I3 and are thereby moved longitudinally through the casing I from end to end thereof, as previously noted.

Preferably, the girts I0 are in the form of round poles or rollers and are provided at one or each end with a gear 20. Along the upper run I8 of the conveyer I3, the teeth of the gears 20, 20 mesh with the teeth of stationary gear racks 2|, which are maintained in fixed position in and with respect to the casing I, which, as the upper run IB of the conveyer I3 advances from the feed end toward the discharge end of the casing I, effects rotation of the girts I0 and causes the web W to change its position with respect to the girts I 0 continuously as the girts are advanced through the drying chamber.

The side chains I2, I2 of the conveyer I3 pass around sprockets I4, I5, I6 and I1, which may be supported and driven in any suitable manner and by any suitable means to effect either continuous or intermittent movement of the conveyer and the girts I8 forming part thereof.

The side chains I2 are provided with supporting rollers 9 which are adapted to travel along tracks 8, at opposite sides respectively of and extending horizontally through the casing I for supporting the upper run I8 of the conveyer I3 therein.

In one form of the invention, shown in Figs. 1, 3 and 4, and as disclosed in the aforesaid copending application, the upper turned portions :c of the loops or festoons X which pass around the upper sides of the rotary girts I are pressed into engagement with the girts by a series of freely rotatable cylindrical weights or hold-down rollers 25, 25, which are arranged with the axes thereof respectively lying in vertical planes coinciding with the axes of the girts I8, I8.

The hold-down rollers are provided with trunnions 25 at their opposite ends which are loosely mounted in vertical slots 24 formed in brackets 23 which are secured to side links 21 of a pair of laterally spaced endless chain belts 28. The brackets 23 are spaced along the` chains 28 in accordance with the spacing of the bearings for the trunnions II of the girts chains I2 of the conveyer I3, to maintain contact between the rollers 25 on the lower runs of the chains 28 with the girts I0 in the upper run I8 of the conveyer I3.

The chains 28 pass around sprockets 28, 38,

3| and 32 and are provided with rollers 33 which, throughout the lower runs 34 of the chains 28, ride on rails 35. The rails 35 are spaced above and extend parallel to the rails 8 on which the rollers 9 of the upper run I8 of the conveyer I3 are supported.

The chains 28, or any of the sprockets 29 to 32 over which these chains are trained, may be driven by any suitable means coordinated with the driving mechanism for the eifect concurrent equal speed movement of the lower run 34 of the chains 28 with the upper run I8 of the conveyer I3.

The mechanism so far described corresponds substantially to that disclosed in the aforemenf tioned copending application.

The present invention contemplates the provision of discharge nozzles 48, 48 for the drying medium arranged with elongated mouth slots 4IY 4I thereof disposed parallel to and in vertical alignment with the open spaces between the girts I8, IIJ and which, by reason of the draping of the web W over and between said girts, corresponds to the open upper ends or mouths Y of the festoon loops X. The discharge mouths or slots 4I for the drying medium extend transversely of the drying chamber, preferably for the full length of the girts III, I8, between the side chains I2, I2, with the slots 4D, 48 parallel to and substantially equi-distantly placed between the axes of the girts I0.

The nozzle mouths or slots 4I, in the form of the invention shown in Figs. l to 4 inclusive, are formed by providing a shield plate of substantially semi-circular or other tional shape around the upper side of each of the hold-down rollers 25, with the lower edges 43, 43 of said shield plates, which collectively constitute sections or parts of the nozzle series, terminating in a substantially horizontal plane I0 along on the desired cross-secconveyer I3 to plane tangent to IIJ in the upper slightly above a similar common the top surfaces of the girts I0, run I8 of the conveyer I3.

The arcuate nozzle sections 42, in the present instance, are respectively carried by the brackets 23, 23 which function also as the guides for the trunnions of the hold-down rollers 25, each of said brackets being provided with an inwardly extending flange 44 which overlies each nozzle element 42, at the end thereof, and to which said nozzle forming element is secured, as by rivets 45 in the present instance.

As the lower runs 34 of the chains 28 and the upper runs I8 of the chains I2 travel concurrently, at equal speeds, to maintain the holddown rollers 25, 25 in vertical parallel alignment with the girts I8, the mouths 4I, 4I of the nozzles 48, formed by adjacent nozzle elements 42, 42, travel concurrently with said chains and remain at all times in vertical alignment with the open ends Y of the loops or festoons X.

Air or other drying medium is supplied to the nozzles 48 for discharge through the mouths or slots 4I thereof by any suitable means such, for example, as the fans 46, 46 shown in Fig. 2. The fans 45, 45 are driven by motors 41, 41 respectively. The motors 41 are installed in the outer longitudinal side walls 48, 48 of the drier casing I.

In the present instance, each fan 46 is mounted within a cylindrical air duct 49. The ducts 49 extend laterally outward from longitudinal vertical partitions 58, 58 which extend substantially the full length of the drier I and provide air circulating chambers 5I, 5I along each side of the drier. Heating or other tempering units 52, 52 for the drying medium circulated through the drier are located in the side chambers 5 I, 5I.

The fans 46, 46 draw the tempered medium from the upper ends of the chambers 5I, 5I and direct it in opposite directions inwardly toward the center of the drier I, into a space or charnber 53 formed between the lower run 34 of the traveling nozzle unit, which is composed of the side chains 28, 28 and the nozzle elements 42, 42, and the upper run 54 oi said nozzle unit.

Within the space 53 is a series of air bales 55. The bales 55, 55 at opposite sides respectively of the median vertical longitudinal plane of the drier are arranged in vertically and laterally spaced divergent relation to each other within the space 53, so that air, etc., driven toward said median plane by said fans is divided in its horizontal flow in opposite directions and diverted downwardly in the nozzle space 53 into and through the nozzle mouths or slots 4I, 4I formed along the bottom of said space 53, whereby said tempered drying medium passes downwardly into the open ends Y of the loops X.

The iiowing air etc. passing from the nozzles 48, 48 into the open ends Y, Y, of the loops X, X, causes the web W in the lower side parts of said loops to belly outwardly from the free hanging position shown in broken lines in Fig. 3 to the full line positions shown in said iigure, the loops being foreshortened vertically in accordance with the lateral bellying, as shown in Fig. 3.

The air driven down into the bellies Z of the loops X, upon striking the bottoms of the loops moves outwardly in opposite directions through the open sides of the loops. The drying medium escapes around the marginal edges of the web W into the main drying chamber 56 of the drier through which the loops are conveyed by the conveyer I3, and passes into the side chambers I, 5I for recirculation by the fans 46, 46.

The bottom wall 51 of the drying chamber 56 is perforated to permit the air to escape therefrom into a bottom compartment 58 in the drier through which the return or lower run 59 of the conveyer I3 moves. In the lower compartment 58 the air escapes laterally through openings 60, 60 in the lower portions of the partitions 50, 50 into the lower ends of the circulating compartments 5I.

The downward driving of the air in the bellies Z of the loops X, and the escape of the air transversely of the web toward the opposite marginal edges thereof maintains the web in a smooth condition, eliminating wrinkles and folds forming in the web W, which heretofore have been a source of annoyance in loop driers prior to the present invention.

The web W is formed into the loops X, X successively, by passing over a rotating drum 6I which feeds the web downwardly between adjacent girts I0, I9, either while the upper run I8 of the conveyer I3 moves at a low rate of speed beneath said drum or while the conveyer I3 is at rest. In either case, as each girt I0 successively moves under the lower edge 62 of a vertically depending air nozzle 63 air escaping from said end of said nozzle impinges upon the web W and folds it smoothly over the top of the girt I0 passing beneath the nozzle, thereby completing one loop X and starting the next loop X by effecting a tucking of the web X down between the girt passing under the nozzle and the next succeeding girt.

A flow of air in the present instance is provided in the nozzle 63 by a suitable fan 64 drawing air from the outside atmosphere ,and driving it into a feed conduit 65 from which the nozzle 63 extends, said air being drawn in part from the interior of the drier through the conduits 66 and intermingling with fresh air drawn from the outside atmosphere by the fan and driven into the open end 61 of the conduit 65.

Adjacent the discharge end 3 of the drier casing I, the web W is drawn out of the loops X, X successively, by a, rotating drum 68, over a roll 69 extending transversely across the casing above the upper run I8 of the conveyer I3.

Obviously, in some instances at least, the hold-down rollers 25 may be eliminated and the force of the air driven through the discharge slots 4I of the nozzles 48 into the loops X may be depended upon to hold the web W forming the upper portions :I: of the loops X into such firm contact with the peripheral faces of the rotating girts I0 as to insure traction between the web and the girts, in which case the nozzles 40 will travel with the conveyer I3 and insure such gripping of the web by the rotating girts, from the point of formation of the web into the loops at one end of the drier to the point of withdrawal of the web from the loops adjacent the opposite end of the drier.

The same general effect may be obtained by the use of a series of nozzles 40a, 49a, see Fig. 5, wherein the nozzle elements 42a, 42a are integrally attached at their opposite ends to longitudinally extending carrier beams 28a, 28a and by moving the beams 28a, 28a and the nozzle elements 42a, 42a concurrently with and at the same speed as the upper run Ia of the conveyer I3 through a distance substantially equal to the distance between the axes of adjacent girts Illa, IUa and then rapidly reversing the direction of the movement of the nozzle structure a like distance for a repeat of the cycle. In this way the continuity of the ow of medium from the nozzles 40a, 40a into the respective open ends of the loops is but momentarily interrupted.

Any suitable mechanism may be provided for effecting such an uneven or unbalanced reciprocatory movement of the frame members 28a, such, for example, as providing a rotary shaft 10 with a cam 1I having a low part 12 and a high part 13 immediately adjacent each other and connected by a substantially radial cam surface 15 providing the quick return movement from the high point 13 to the low point 12 of the cam under the infiuence of springs or other suitable counter-acting elements 16, said cam surface working against a cam follower 11 rotatably mounted on one end of a link 18, the opposite end 19 of which may be pivotally connected to a lever 8D having a fixed pivot 8| at one end and its opposite end 82 connected directly or through a link 83 to each of the side members 28a.

With the cam rotating in the direction of the arrow a, the nozzle structure Would be moved slowly in the direction of the arrow b at the same speed at which the upper run I8 of the conveyer I3 was moving in a like direction, as the cam surface moves past the cam follower 11 from the low point 12 to the high point 13. Immediately upon reaching the high point 13, the cam follower 11 moves along the sharp decline 15 in the cam surface under the inuence of the springs 16 and rapidly moves the nozzle structure in a reverse direction corresponding to the arrow c, for realigning the nozzle mouths 40a with the open ends Y of the loops X for a repeat of the cycle.

As shown in Fig. 6, a somewhat similar effect may be obtained by securing the longitudinal members 28h of the nozzle structure in a fixed position within the casing and by moving the upper run Ib of the conveyer intermittently in short steps corresponding to the spacing between the axes of the girts IIlb, said movement being rapid, as compared with the lapses of time between such movements in order to reduce the period of interrupted continuity of the flow of the drying medium from `the mouths 40h of the xed nozzle unit into the spaces between the girts I0b, to a minimum. Any suitable mechanism may be provided for effecting such movement of the girt supporting conveyer, for example, one of the shafts to which a pair of the sprockets I5, I5 over which the side chains I2, I2 are trained, may be provided with a ratchet wheel and engaged by a pawl 9I pivotally mounted on one end 92 of a lever 93, said lever being rockable about the shaft 94 on which the ratchet wheel 96 is secured. The second arm 95 of the lever 93 may be connected to a link 96 to any suitable mechanism capable of providing a rapid movement of the pawl 9| in one direction to advance the upper run I 8b of the girt carrying chains and a leisurely movement of the pawl in the opposite direction. For example, the link 96 may be of the same construction as the link 18, shown in Fig. 5. This link may be provided with a cam follower operating against a cam having high and low points similar to the high and low points 12 and 13 and a cocking surface extending from the low to the high point for leisurely moving the pawl lever 95 in one direction against the tension of a spring 91, and a sharp decline 15 between the high and the low points of the cam for quickly moving the pawl 9| in the opposite direction, under the action of the spring 91. The device is tripped by the cam follower dropping oli the high point 'i3 of the cam onto the sharp decline 'I5 and returning to the low point l2 of the cam.

I claim:

l. In a estoon dryer, a plurality of horizontal laterally spaced parallel loop supports, a plurality of separate iuid nozzles above said supports and respectively aligned vertically with the spaces between said supports, means for horizontally advancing said supports and said nozzles concurrently, and means for building up a fluid pressure above said nozzles to escape through said nozzles into said spaces between said supports.

2. In a iestoon drier, an endless belt conveyer comprising side chains and laterally spaced transversely extending girts having their opposite ends respectively carried by said side chains, said conveyer including horizontal upper and lower vertically spaced runs, a second endless belt comprising side chains and laterally spaced uid nozzle elements extending transversely of and secured at their opposite ends to the side chains of said second belt, said second belt including upper and lower vertically spaced runs with the lower run of the second belt parallel to and adjacent the upper run of the iirst said belt, the spaces between said nozzle elements in the lower run of the second belt forming fluid nozzle openings in vertical alignment with the spaces between the supports on the upper run of the first belt, means for concurrently advancing said adjacent runs of said belts, and means for building up a fluid pressure above said nozzle openings to escape through said nozzle openings downwardly into the spaces between said supports aligned with said nozzle openings.

3. In a festoon drier, an endless belt conveyer comprising side chains and laterally spaced transversely extending girts having their opposite ends respectively carried by said side chains, said conveyer including horizontal upper and lower vertically spaced runs, a second endless belt comprising side chains and laterally spaced fluid nozzle elements extending transversely of and secured at their opposite ends to the side chains of said second belt, said second belt including upper and lower vertically spaced runs with the lower run of the second belt parallel to and adjacent the upper run of the iirst said belt, the spaces between said nozzle elements in the lower run of the second belt forming fluid nozzle openings in vertical alignment with the spaces between the supports on the upper run of the first belt, means for concurrently advancing said adjacent runs of said belts, means for building up a fluid pressure above said nozzle openings to escape through said nozzle openings downwardly into the spaces between said supports aligned with said nozzle openings, means along the path of travel of said supports in said upper run of said iirst belt for rotating said supports enroute, and hold-down rollers carried by said second belt in vertical alignment, with said rotating supports respectively. said hold-down rollers being respectively mounted on the side chains of said second belt under the nozzle elements carried by said second belt with the nozzle openings between said hold-down rollers.

4. In a drier of the kind described, a nozzle structure composed of a plurality of nozzle elements each in the form of a semi-circular plate. common supports for the ends of a plurality of said elements arranged with the longitudinal edges of adjacent elements spaced apart laterally to produce a nozzle opening therebetween and means for actuating said common supports longitudinally to eiiect lateral movement of said plurality of nozzle elements in unison.

5. In a drier of the kind described, a nozzle structure composed of a plurality of nozzle elements each in the form of a semi-circular plate, common supports for the ends of a plurality of said elements arranged with the longitudinal edges of adjacent elements spaced apart laterally to produce a nozzle opening therebetween, said common supports being in the form of endless belts composed of a plurality of pivotally connected chain links.

6. In a festoon drier, a plurality of horizontal laterally spaced parallel loop supports, a plurality of separate fluid nozzles above said supports and respectively aligned vertically with the spaces between said supports when said supports and said nozzles advance concurrently, means for horizontally advancing said supports and said nozzles concurrently for a predetermined distance equal to one or a multiple of the distances between each two supports, and means for rapidly returning said series of nozzles a similar distance into registry with a succeeding group of spaces in recurrent cycles.

'7. In a festoon drier, a plurality of horizontal laterally spaced parallel loop supports, a plurality of separate fluid nozzles above said supports and respectively aligned vertically with the spaces between said supports when there is no relative movement between the nozzles and the supports, means for driving air from said nozzles into said spaces exclusively, and means for moving said supports rapidly as a unit, relative to said nozzles to effect realignment of said nozzles with succeeding spaces respectively between said supports.

8. In a iestoon drier for continuous materials movable longitudinally through the drier, a plurality of horizontal, laterally spaced, parallelv support elements over which the material is draped in loose free hanging loops with spaces between the successive loops; means for moving said support elements longitudinally through the drier; means for building up a fiuid pressure above said support elements to pass downwardly against said material and into said spaces; a series of guard elements in the form of semi-circular plates disposed between said support elements and said means for building up the fluid pressure, said series of guard elements overlying said support elements and normally aligned therewith when there is no relative movement between said support elements and said guard elements, the opposite edges of succeeding guard plates pointing downwardly in laterally spaced relation above said spaces for deecting said fluid pressure from contact with the material lying in contact with said support elements and functioning as a series of nozzles to increase the velocity of said fluid pressure passing into said spaces; and means for producing relative movement between said series of guard elements and said plurality of support elements to effect successive alignment of said nozzles with said spaces.

ALPHEUS O. HURXTHAL. 

